Method of controlling insects using quinoxalinyl n{11 -oxide phosphates

ABSTRACT

Novel quinoxalinyl N4-oxide phosphates together with their preparation and use for controlling insects and arachnids are disclosed. They have the formula:   WHEREIN R and R1 each are selected from the group consisting of lower alkyl, lower alkoxy, lower alkylthio, phenyl, halosubstituted phenyl, lower alkyl-substituted phenyl, and NR2 groups wherein R2 is hydrogen or lower alkyl; X is sulfur or oxygen; and Y is hydrogen, halogen, lower alkyl or lower alkoxy.

United States Patent 1 Miller et al.

[11] 3,708,580 [451 Jan. 2, 1973 [75] Inventors: Bernard Miller,Plainsboro; :lackson Pollard English, Princeton, both of NJ.

[73] Assignee: American Cyanamid Company,

Stamford, Conn.

[22] Filed: July 14, 1970 [21] Appl. No.: 62,737

Related U.S. Application Data [62] .Division of SenNo. 658,598, Aug. 7,1967, Pat. No.

[52] US. Cl. ..424/200 [51] Int.,Cl. ..A0ln 9/00, AOln 9/36 [58] Fieldof Search ..424/200 [56] References Cited UNITED STATES PATENTS2,922,791 1/1960 Rockett ..260/294.8

FOREIGN PATENTS OR APPLICATIONS 681,443 ll/l966 Belgium ..260/250Primary ExaminerJerome D. Goldberg Assistant Examiner-Allen J RobinsonAttorney-I-larry H. Kline 57 ABSTRACT Novel quinoxalinyl N oxidephosphates together with their preparation and use for controllinginsects and arachnids are disclosed. They have the formula:

wherein R and R each are selected from the group consisting of loweralkyl, lower alkoxy, lower alkylthio, phenyl, halo-substituted phenyl,lower alkylsubstituted phenyl, and NR, groups wherein R, is hydrogen orlower alkyl; X is sulfur or oxygen; and Y is hydrogen, halogen, loweralkyl or lower alkoxy.

12 Claims. No Drawings oxide phosphates, a process for the preparationthereof, and the use of such compounds for controlling insects andarachnids. More particularly, the invention relates to new quinoxalinylN -oxide phosphates having the formula:

wherein R and R each are selected from the group consisting of loweralkyl, loweralkoxy, lower alkylthio, phenyl, halo-substituted phenyl,lower alkyl-substituted phenyl, and NP, groups wherein R is hydrogen orlower alkyl; X is sulfur or oxygen; and Y is hydrogen, halogen, loweralkyl or lower alkoxy. The invention further relates to a process forthe preparation of the above-characterized compounds and to theapplication of the same on plant life'for the control of insects andarachnids.

Illustrative compounds contemplated by the invention are, for instance:

2 N,N-dim ethyl O-ethyl 0-2-quinoxalinyl N-oxide phosphorothioamidate.

, Advantageously, the compounds of the invention can I be preparedconveniently by a plurality of reactions. These include reacting a2-nitroaniline of the formula:

wherein Y is hydrogen, halogen, lower alkyl or lower alkoxy, withdiketene, preferably in the presence of mercuric acetate or othersuitable mercury salts, to

yield a nitroacetoacetanilide of the formula:

which, when treated with a strong base, such as potassium or sodiumhydroxide, yields a quinoxalinone N- oxide having the formula:

Reaction of the latter quinoxalinone N"-oxide with a halogenatedphosphorylating agent of the formula:

Diethyl2-quinoxalinylN-oxide phosphate, (E I O-methyl O-ethylo-2-quinoxalinyl N -oxide phosphorothioate, R1 O-methyl o-2-quinoxalinylN oxide phenwhereinzisahalogen ylphPsphomthmte yields the quinoxalinylN-oxide phosphate of the ini qz o'z'qumoxahnyi N 'oxlde ventionrepresented by the formula:

p osp orami a e, 0,0-dimethyl 0-2-quinoxalinyl N-oxide phosphorothioate,0e 0,0-diethyl 0-2-quinoxalinyl N -oxide 7 L6; phosphorothioate, I X R0,0-diethyl 0 -6-methyl-Z-quinoxalinyl N -oxide phosphorothioate, v0,0-dimethyl 0 -6-methyl-2-quinoxalinyl N" -oxide R1 phosphorothioate, vv

0,0-dimethyl 0-6-chloro-2-quino xalinyl N -oxide phosphorothioate, I v 1wherein R,R,,XandYare defined above. 0,0-'dieth l 0 8-chloro-2-uinoxalin l N-oxide Gra hically, the above overall reactions may be I vq 3 P v phosphorothioate,an'd shown asfollows:

NO2 CH2-C'CHZ NO2 Y Y *NIIZ o --NH-(fi--CH;-fi3-CHI 09 o N (ID NO;strong base NH-C-CH;-CCH; =0

ll 11 f (111) /N\ R\ Be /N\ Y r z Y R R P F wherein R, R X and Y are asdefined above.

In the preparation of the ni troacetoacetanilide in step (I) above, itis desirable to disperse the nitroaniline reactant in a solvent, such asacetic acid or acetone, and conduct the reaction with the diketene inthe presence of mercuric acetate or other equivalent mercury salts and aketonic solvent, such as acetone, methyl ethyl ketone or methyl isobutylketone. The reaction may be carried out at between about C. and 100C.,but is preferably held at between about 25C. and 60C. Resultantnitroacetoacetanilide may then be separated from the reaction mixture byany known means, such as filtration or centrifugation, then washed withwater and treated with a strong base, such as sodiumhydroxide,'potassium hydroxide and equivalents thereof, preferably as anaqueous solution. A cyclized product, namely, the quinoxalinone N -oxideis obtained. For cyclization, reaction temperatures are generallycarried out 'at an elevated temperature between about 30C. and 100l 85C. Treatment of the quinoxalinone N-oxide with a strong base, such aspotassium t-butoxide and an organic solvent, such as dimethylsulfoxideor dimethylformamide, followed by phosphorylation at between 0C. and70C. with a halogenated phosphorylating agent yields the desiredquinoxalinyl N"-oxide phosphate or thiophosphate as above defined.

Exemplary nitroanilines employed in step (I) include:

2-nitroaniline,

4-chloro-2-nitroaniline,

2-nitro-p-toluidine,

6-chloro-2-nitroaniline,

4-methoxy-2-nitroaniline,

4-ethoxy-2-nitroaniline, and

4-ethyl-2-nitroaniline.

Illustrative typical phosphorylating compounds employed in step (III)are, for instance:

0,0-dimethyl phosphorochloridothioate,

0,0-diethyl phosphorochloridothioate,

O-methyl-O-ethyl phosphorochloridothioate,

0,0-diisopropyl phosphorobromidothioate,

0,0-di-n-butyl phosphorochloridothioate, 0,0-dimethylphosphorochloridate,

0,0-diethyl phosphorochloridate,

O-ethyl ethanephosphonochloridothioate,

phospho'ramidochloridothioate,

O-ethyl phenylphosphonochloridothioate,

O-ethyl-N-isopropyl phosphoramidochloridothioate,

O-ethyl-N-methylphosphoramidochloridothioate,

S,S-diethyl phosp horochloridotrithioate, and

Diethylphosphinothioyl bromide.

The compounds of the present invention are excel lent insecticides andarachnicides. They are applied to either plant foliage or to an area inwhich plants are grown to protect them against the ravages of a varietyof insects and arachnids. Further, they are effective against both theadult and larval stages of insects possessing both systemic activity anda low order of mammalian toxicity as well as non-phytotoxicity atpesticidally effective rates. Advantageously, the compounds of theinvention lend themselves to use with LV (e.g., Low Volume) and ULV(e.g., Ultra Low Volume) dispersing equipment as well as withconventional application equipment. I

In general, the compounds of the invention may be employed in solid orliquid form. They may be used as dusts, dust concentrates, wettablepowders, emulsifiable concentrates, granular formulations, and as lowvolume and ultra low volume concentrates (hereinafter referred to as LVand ULV concentrates, respectively).

Solid formulations, such as dusts, dust concentrates, and wettablepowders are readily prepared by admixing usually about 25 percent to 95percent by weight of the active compound with about 5 percent to percentby weight of a finely divided carrier, such as attapulgite, kaolin,diatomaceous earth, silica, talc, and the like. A small amount, usuallyabout 0.2 percent to 2.0 percent, by weight, of a surfactant may also beadded, if desired. Wettable powders are made in essentially the samemanner as the solids but usually about 0.2 percent to 2.0 125 percent byweight of an emulsifying agent is added to the formulation and thewettable powder is dispersed in water and applied as a liquid spray.Among the emulsifying agents'useful in the above preparation are thealkyl and aryl sulfonates, polyoxyalkylene-fatty acid esters, andpolyglycol ethers. These emulsifying agents may also be used in thepreparation of the emulsifiable concentrate formulations. In theseformulations the active ingredient is generally dissolved in an organicsolvent, such as a lower alkanol, benzene, acetone, methyl ethyl ketone,cyclohexanone, or the like, with a small amount of emulsifier added. Theconcentrate is usually then dispersed in water just prior toapplication. 7

For LV and ULV applications, the compound may be directly applied as atechnical grade liquid. Alternatively, where the compound is a solid, itis dissolved in a small amount of a relatively non-volatile solventhaving a flash point above about l25F.; a specific gravity at 60/60 F.exceeding about 0.888; and an evaporation rate not exceeding 25 percentin 6 hours at 25C. and 48 percent relative humidity, such as Panasol,and applied as such. Further, malathion, chemically identified as0,0-dimethyl phosphorodithioate of diethyl mercaptosuccinate, and heavyaromatic solvents having a mixed aniline point of F. or below andaromatic content above 60 percent are excellent solvents or diluents forthis purpose. In these LV and ULV applications, the concentrate isapplied as a finely divided mist or spray, generally with aerialapplication equipment.

The invention may be furtherunderstood by referring to the examples setforth below, which are to be taken as merely illustrative. They are notintended to be construed as limitative. All parts are by weight unlessotherwise stated.

EXAMPLE 1 Preparation of 4'-Chloro-2'-Nitroacetoacetanilide In asuitable reaction vessel 345 parts of 4-chloro-2- nitroaniline aresuspended in 6O parts (by volume) of glacial acetic acid. 1.3 Parts ofmercuric acetate and 44 parts (by volume) of a 50 percent solution ofdiketene in acetone were added and the mixture stirred at 25C.

for 5 minutes. An additional 2 parts of mercuric acetate are then added.The temperature rises to 44C. after 40 minutes. The mixture is nextcooled to 30C. and then allowed to stand at room temperature for 2 days.100

Parts (by volume) of water are added to the stirred mixture which isallowed to settle. The water is poured.

off and the residual solids dissolved in methanol and crystallized bythe addition of water. The yield is 29.5 parts, equivalent to 57.5percent of theoretical, having a melting point of between 81C. and 835C.

EXAMPLE 2 Repeating the procedure of Example 1 in every detail exceptthat 4-chloro-2-nitroaniline is substituted for 2-nitro-p-toluidine inthe above example, a 57 percent yield'of4'-methyl-2-nitroacetoacetanilide, melting point 99C.-100C., isobtained. The structure of 7 this product is confirmed by its NMRspectra.

' EXAMPLE 3 Substituting 6-chloro-2-nitroaniline for 4-chloro-2nitroaniline in the procedure of Example 1 above, there is obtained a 62percent yield of 6'-chloro-2'- nitroacetoacetanilide, melting pointequal to 145C.- 146C. The structure is confirmed by'NMR spectra.

EXAMPLE 4 Preparation of 6-Methyl-2-Quinoxa1inone N-oxide To a suitablereaction vessel are added 8.4 parts of2'-nitro-4'-methylacetoacetanilide. The latter is then suspended in 150parts (by volume) of 18 percent aqueous potassium hydroxide solution.The mixture is next stirred'at 55C.-60C. for 341 of an hour, and thenheated to 75C.80C. for k hour. It is then allowed to cool and standovernight at room temperature. The mixture is extracted with chloroformand the aqueous layer is diluted to 400 parts (by volume) and acidifiedwith dilute hydrochloric acid. brown precipitate forms and is filteredoff and washed with dilute sodium bicarbonate solution. It is thendissolved in IN sodium hydroxide and reprecipitated with 1N hydrochloricacid to yield 5.7 parts, equal to 92 percent of theoretical, of a darkbrown solid. Recrystallization from acetic acid does not'appear tochange its infra-red spectrum.

EXAMPLE 5 Preparation of 6-chloro-2-quinoxalinone N-oxid e The procedureof Example 4 is followed in every detail except that2-nitro-4'-chloroacetoacetanilide is reacted with aqueous sodiumhydroxide to yield an 89 percent yield of 6-chloro-2-quinoxalinoneN-oxide.

EXAMPLE 6 Repeating the procedure of Example 4 in every detail exceptthat 8-chloro-2-quinoxalinone N-oxide having a melting point of259C.260C. (dec.) in a 75 percent yield is obtained employing6'-chloro-2- nitroacetoacetanilide in lieu of 2'-nitro-4'-methylacetoacetanilide.

EXAMPLE 7 Preparation of 0,0-Dimethy1 O-Z-quinoxa'linyl N -oxidePhosphorothioate 5.0 Parts of quinoxalinone N-oxide are suspended inparts.(by volume) of dime'thylsulfoxide in a suitable reaction vessel.3.50 Parts of potassium t-but'oxide are added to give a dark redsolution which is cooled in ice. I

Next, 5.1 parts of 0,0-dimethyl phosphorochloridothioate are addedrapidly. After 1 minute, the solution is neutral in pH. It is pouredonto a mixture of ice water and methylene chloride. The organic layer iswashed three times with water, dried over magnesium sulfate and thenevaporated to yield 5.8 parts of dark red oil. The latter ischromatographed on magnesium silicate to give 3.7 parts of pale redsolid. Recrystallization from carbon tetrachloride yields 2.4 parts ofpale orange solid, possessing a melting point equal to 97C.98.5C., and0.4 part of pale yellow solid, having a melting point equal to 98C.99C.

Analysis (in percent): Calcd. for PN SO C H Calcd: P, 10.83; N, 9.79; S,11.6; C, 41.9; H, 3.84 Found: P, 10.64; N, 9.53; S, l 1.24; C, 41.8; H,4.09

EXAMPLE 8 Preparation of 0,0-Diethyl 0-2-quinoxalinyl N -oxidePhosphorothioate The procedure of Example 7 is repeated in every detail,except that 3.0 parts of quinoxalinone N -oxide, 2.10 parts of potassiumt-butoxide, and 3.50 parts of 0,0-diethyl phosphorochloridothioate areemployed as reactants. Chromatography on magnesium silicate yields 1.90parts of an orange solid. Recrystallization from petroleum ether yields0.2 part of solid, having a melting point equal to 54C.56C., and 0.8part having a melting point of 52C.5 5C.

Analysis (in percent): Calcd. for PN SO C H Calcd: P, 9.87; N, 8.92; S,10.2; C, 45.9 H, 4.98 Found: P,9.67; N, 8.80; S, 10.3; C, 45.1 H, 4.84

EXAMPLE 9 Preparation of 0,0-dimethyl 0-6-methyl-2-quinoxalinyl N -oxidePhosphorothioate Repeating the procedure of Example 7 in every detail,there is obtained a good yield of the abovenamed compound having amelting point of 124C.-

' 125.5C. by substituting 6-methyl-2 quin oxalinone N- oxide forquinoxalinone N-oxide.

Analysis (in percent): Calcd. for PN SO C H Calcd: P, 10.32; N, 9.33; S,10.78; C, 44.0; H, 4.36 Found: P, 10.15;N,9.18;S, 10. 8l;C,44.1;H,4.23

EXAMPLE 10 Preparation of 0,0-diethyl 0-6-chloro-2-quinoxalinyl N -oxidePhosphorothioate Substituting 6-chloro-2-quinoxalinone N-oxide forquinoxalinone N-oxide and 0,0-diethyl phosphorochloridothioate for0,0-dimethyl phosphorochloridothioate in the process of Example 7 andrepeating that process in every detail, there is obtained 0,0-diethyl0-6-chloro-2-quinoxalinyl N-oxide phosphorothioate possessing a meltingpoint equal to 84C.-A86C.

Analysis (in percent): Calcd. for PN SO CLC H Calcd: P, 8.88; N, 8.03;S, 9.19; Cl, 10,2; C, 41.3; H, 4.05 Found: P, 8.73; N, 8.06; S, 8.59;Cl, 9.87; C, 43.6; 5 H, 4.00

EXAMPLE 1 1 Preparation of 0,0-diethyl 0-6-methyl-2-quinoxalinyl N-oxidePhosphorothioate Found: P, 9.54; N, 8.61; s, 10.24; c, 48.5; 11, 5.41

EXAMPLE 12 Preparation of O,'O-diethyl 0-8-chloro-2-quinoxalinyl N-oxide Phosphorothioate EXAMPLE 13 Preparation of Diethyl 2-quinoxaliny1N -oxide Phosphate 40 The above named compound whose melting point is63.0C.'-64.5C. is prepared using the process of Example 7 byquinoxalinone N -oxide with diethyl phosphorochloridate.

Analysis (in percent): Calcd. for 1 N o,c,,n,,; Calcd: P, 10.41, N,9.40; C, 48.3; H, 5.04 Found P, 10.41;N,9.39;C,48.4;H,5.08

EXAMPLE 14 Preparation of Diisopropyl 2-quinoxalinyl N -oxide PhosphateFollowing the process of Example 13 but substituting 0,0-diisopropylphosphorochloridate for 0,0-diethy1 phosphorochloridate yields theabove-named compound whose melting point equals l08.5C.-l 10C.

Analysis (in percent): Calcd. for PN O C H Calcd: P, 9.51; N, 8.60; C,51.5; H, 4.30 Found: P,

EXAMPLE 15 Preparation of 0,0-diisopropyl 0-2-quinoxalinyl N"- oxidePhosphorothioate The procedure of Example 7 is repeated in every detailexcept that 0,0-diisopropyl phosphorochloridothioate is employed inplace of 0,0-

dimethyl phosphorochloridothioate to obtain a good yield of theabove-named product whose melting point is 76.5C.78.0C.

Analysis (in percent): Calcd. for PN SO C H Calcd: P, 9.07; N, 8.18; S,9.36; C, 49.2; H, 5.56 Found: P, 8.97; N, 8.18; S, 9.38; C, 49.3; H,5.66

EXAMPLE 16 The insecticidal activity of the compounds of the inventionis illustrated by the following tests wherein the procedures employedand the results are set forth below.

Bean Aphid Aphisfabae Scopoli Representative compounds are tested as 0.1percent, 0.01 percent, and 0.001 percent solutions or suspensions in 65percent acetone/35 percent water. 2-inch fiber pots, each containing anasturtium plant 2 inches high and infested with about 150 aphids 2 daysearlier, are sprayed with test solution to give complete coverage of theaphids and the plants. The sprayed plants are laid on their sides onwide enamel trays which have had the edges coated with No. 50 SAE oil asa barrier. Mortality estimates are made after holding for two days atF., and 50 percent R.H.

Southern Armyworm Prodenia eridania (Cramer) The 0.1% and 0.01%solutions from the aphid test are also used for this test. Sieva limabean primary leaves are dipped for 3 seconds in the test solution andset in a hood on a screen to dry. When dry, each leaf is placed in a4-inch petri dish which has a moist filter paper in the bottom and 10third-instar armyworm larvae about inch long. The dishes are covered andheld at F., and 60 percent R.H. After 2 days, mortality counts andestimates of the amount of feeding are made. Compounds showing partialkill and/or inhibition of feeding are held an extra day for furtherobservations.

Confused Flour Beetle Tribolium confzlsum Jacquelin duVal Compounds areformulated as 1 percent dusts by mixing 0.1 part of the compound with9.9 parts of talc, wetting with 5 parts (by volume) of acetone andgrinding with a mortar and pestle until dry. Mg. of this 1 percent dustare then blown into the top of a dust settling tower with a short blastof air. The dust is allowed to settle on 4-inch petri dishes for 2minutes, giving a deposit of approximately 87 mg./sq. foot of the lpercent dust. The dishes are removed and 25 adult confused beetles areadded immediately. The dishes are held for 3 days at 80F. and 60 percentR.H. following which mortality counts are made.

Large Milkweed Bug Oncopellusfascialus Dallas The 1 percent dustsdescribed above are used in this test. 25 Mg. of the 1 percent dusts aresprinkled evenly over the glass bottom of a 7-inch diameter cage givinga deposit of approximately 94 mg./sq. foot of the l percent dust. Wateris supplied in a 2-ounce bottle with a cotton wick, 20 adult bugs areadded and a screen cover placed on the top. Mortality counts are madeafter holding for three days at 80F. and 60 percent R.H.

German Cockroach Blatlella germanica (Linnaeus) The procedure is thesame as for the large milkweed bug test, except that in this test onlyadult males are used.

Housefly Musca domestica Linnaeus Groups of adult female houseflies arelightly anesthetized with carbon dioxide, placed in widemouth pint masonjars, and covered with a screen cap. The test compound is formulated asan emulsion containing ppm of test material, an emulsifier, acetone, andwater. The mouth of the vial is covered with a sin- Southern CornRootworrn Diabrotica undecimpunctata howardi Barber screen cap so thatthe flies can feed on the solution through the screen. Mortality countsare made after 2 days at F.

le la er of cheesecloth, inverted and laced on the below. 8 y

'lABLE 1 Southern Southern Bonn aphid nrmyworm corn root- TC, MB, G05IIousdily, \voru\,50 Compound 0.1% 0.01% 0.001% 1% 0.01% 1% 1% 1% 50p.p.m. lbs/acre H \N/ -o1(0om)2 9. 100 100 100 100 100 100 100 v 100 100ea i N OI(OCHa)z i O1(0CglI I 6 v t 100 100 100 100 100 100 80 100 100100 I N 01 O1(OCzHa)2 r N 3,1230,

9 100 100 100 100 50 100 20 35 68 100 i CHsi Y O-l( CI-Ia)z v v I 100100 100 100 100 100 100 T6 I 100 100 100 I 0 l ll \N ,2 :0 2

\ :0-1(0C31l7l)g TABLE IContinued Southern Southern Bean aphid armywormcorn root- 'IC,1 M13,2 GC,3 Houselly, worm, 50 Compound 0.1% 0.01%0.001% 0.1% 0.01% 1% 1% 1% 60 p.p.m. lbs/acre i \N/ OP(OC2H5)2 Control.

lC=IriboZiu.m confusum. MB=Mllkwoed Bug. 3 GC=Gerrnun Cockronch.

EXAMPLE 17 TABLE II TH; The larvicldal activity of illustrativecompounds of 12 it the invention'is shown by the following tests wherein(lomlmuml 01% 9" the compounds of the invention are employed against 9100 mosquito larvae. The procedure used and results ob- 20 1 tained areset forth below in Table 11.

s Common Malaria Mosquito Anopheles i il H i) quadrimaculatus SayLarvicide Test a 1 Grou s of larvae of the common malaria 25 p EXAMPLE1:;

mosquito are transferred with a medicine dropper to a 50 m1. beakercontaining 25 ml. of water. The test compound is formulated as anemulsion containing test material, an emulsifier, acetone, and water.This emulsion is diluted with sufficient 65 percent acetone/ percentwater mixture to give 0.4 ppm of active ingredient in solution when theemulsion and water containing the larvae are admixed. Mortality countsare made after 24 hours at 80F.

The miticidal activity of exemplary compounds of the invention isillustrated by the following test using the two-spotted spider mite.

Two-spotted Spider Mite Tetranychus urticae (Koch) Sieva lima beanplants with primary leaves 3 to 4 inches long are infested with about100 adult mites per leaf4 hours before use in this test. The mite andegg infested plants are dipped for three seconds in the 0.1 percent,0.01 percent and 0.001 percent solutions used in the armyworm tests, andthe plants set in the hood to dry. They are held for 2 days at F, 60percent R.l-l., and the adult mite mortality estimated on one leaf undera stereoscopic microscope. The other leaf is left on the plant anadditional 5 days and then examined at 10X power to estimate the kill ofeggs and of newlyhatched nymphs, giving a measure of ovicidal andresidual action, respectively.

The results are summarized in Table III below.

TABLE III TABLE III Two-spotted spider mites Compound .1% .01% 0.001%

09 v 100 100 100 l 01 /N\ s l \N/ 0- (002115):

N om s {L \N/ O (OCII:|)2

i O-1(OC2lI o p. \N/ o- (ocnm):

i \N/ O-P(0C3H7l)z i \IN/ OI(OC2H5)2 Weclaim:

l. A method for controlling insects and arachnids on living plantscomprising: applying to said plants an insecticidally or arachnicidallyeffective amount of a compound having the formula:

14 wherein R and R are selected from the group consisting of loweralkyl, lower alkoxy, lower alkylthio, phenyl, halophenyl, loweralkylphenyl, lower alkyl-substituted phenyl, and NR groups wherein R ishydrogen or lower alkyl; X is sulfur or oxygen; and Y ishydrogenhalogen, lower alkyl or lower alkoxy.

2. The method according to claim 1 wherein the compound is: 0,0-dimethylO-2'-quinoxalinyl N"-oxide phosphorothioate.

3. The method according to claim 1 wherein the wherein R and R areselected from the group consisting of lower alkyl, lower alkoxy, loweralkylthio, phenyl, halophenyl,. lower alkylphenyl, loweralkyl-substituted phenyl, and NR groups wherein R is hydrogen or loweralkyl; X is sulfur or oxygen; and Y is hydrogen, halogen, lower alkyl orlower alkoxy.

8. The method according to claim 7 wherein the compound is: 0,0-dimethylO-2-quinoxalinyl N -oxide phosphorothioate.

9. The method according to claim 7 wherein the compound is: 0,0-diethylO-Z-quinoxalinyl N -oxide phosphorothioate.

10. The method according to claim 7 wherein the compound is:0,0-dimethyl 0-6-methyl-2-quinoxalinyl phosphate.

Patent No. 3,708,580 ted January 2, 1973 lnv nt fls) Bernard Miller andJackson lollard English It is certified that error appears in theabove-identified patent and that said Letters Patent are herebycorrected as shown below:

In the ABSTRACT "Novel quinoxalin'yl N -oxide" should read QuinoxalinylN -oxide Column 1, line 4, "now No. should read now United States PatentNo.

Column 1, line 6, "to Quinoxalinyl" should read to novel quinoxalinylColumn 1, line 22, "N1 should read NR Column 3, line 20, "and lO0l85 C.should read and 100C.

Column line 20, "2.0 125 percent" should read 2.0 percent Column 14,lines 3 and 4, "lower alkylphenyl, lower alkyl-substituted phenyl, andNR groups" should read lower alkylphenyl, and NR groups Column 1 lines36 and 37, lower alkylphenyl, lower alkylsubstituted phenyl and NRgroups should read lower alkylphenyl, and NR groups Signed and sealedthis 22nd day of May 1973. I

Csf l Attest;

. EDWARD M.FLETCHER,JR. ROBERT GOT-TSCHALK Attesti ng OfficerCommissioner of Patents FORM 5 0-1050 (IO-69) USCOMM-DC 60376-P69 u. s.GOVIIDIIEIIT numnc OFFICE no! o3uau

2. The method according to claim 1 wherein the compound is: 0,0-dimethyl0-2-quinoxalinyl N4-oxide phosphorothioate.
 3. The method according toclaim 1 wherein the compound is: 0,0-diethyl 0-2-quinoxalinyl N4-oxidephosphorothioate.
 4. The method according to claim 1 wherein thecompound is: 0,0-dimethyl 0-6-methyl-2-quinoxalinyl N4-oxidephosphorothioate.
 5. The method according to claim 1 wherein thecompound is: 0,0-diethyl 0-6-chloro-2-quinoxalinyl N4-oxidephosphorothioate.
 6. The method according to claim 1 wherein thecompound is: diethyl 2-quinoxalinyl N4-oxide phosphate.
 7. A method ofcontrolling mosquito larvae comprising: applying to the breeding groundsof said larvae a larvicidal amount of the compound having the formula:8. The method according to claim 7 wherein the compound is: 0,0-dimethyl0-2-quinoxalinyl N4-oxide phosphorothioate.
 9. The method according toclaim 7 wherein the compound is: 0,0-diethyl 0-2-quinoxalinyl N4-oxidephosphorothioate.
 10. The method according to claim 7 wherein thecompound is: 0, 0-dimethyl 0-6-methyl-2-quinoxalinyl N4-oxidephosphorothioate.
 11. The method according to claim 7 wherein thecompound is: 0, 0-diethyl 0-6-chloro-2-quinoxalinyl N4-oxidephosphorothioate.
 12. The method according to claim 7 wherein thecompound is: diethyl 2-quinoxalinyl N4-oxide phosphate.